Foodborne diseases (FBD) are a global public health issue that significantly affects human health, healthcare systems, and socioeconomic development. Foodborne illnesses are usually infectious or toxic and caused by bacteria, viruses, parasites, or chemical substances entering the body through contaminated food.(1) It can cause sudden symptoms of abdominal pain, diarrhea, and vomiting, but most people get better in a few days without treatment. (1)The foodborne illnesses classified into foodborne infection and foodborne intoxication. (3) Foodborne Infections result from the growth of the pathogen in the human body and usually takes serval hours to weeks for symptoms to occur (3). However, foodborne intoxications are caused by chemicals or toxins produced by organisms in the food product and the manifestation appear more rapidly after consumption of contaminated food (shorter onset time) than are infections. (3) Globally, approximately 600 million cases of food poisoning reported yearly, which implies that one person in every ten is affected. (2) In 2022, there were 1188 cases of foodborne disease and 176 food poisoning outbreaks across Saudi Arabia. There were 119 foodborne illness cases in Riyadh in 2022, with 19 food poisoning outbreaks. (4)
The current outbreak of foodborne diseases occurred in a girls' primary school in Riyadh City, Saudi Arabia, on December 21, 2023. On that day, the school had an open day and food served by company from outside. Therefore, we assumed that the food served by the company in the school was the source of the food poisoning outbreak. We conducted a retrospective cohort study to confirm the existence of the outbreak, confirm the diagnosis, determine the causative agent or organism if possible, and recommend preventive measures to be applied to prevent similar outbreaks in the future. In our study, we included all students and staff who ate during the open day in the primary school. We interviewed them and collected sociodemographic and food history by a semi-structured questionnaire. Then, we analyzed the data.
Our study included 259 participants, 257 students, and 2 school staff. The ages ranged between 6-40 years. Most of the cases were falling at 11 years old. Most of the cases were Saudi 83% and 17% were non-Saudi. Among cases, 97.93% had abdominal pain, 57.93% had nausea, 23.44% had vomiting, 18.62 developed diarrhea, and 4.82% had fever. Only 37 cases were seeking medical care and 222 cases were self-limiting. Out of the cases that sought medical attention, only 10 cases were collected stool cultures and the results of tests were negative. There were no hospitalizations or deaths, and all cases were discharged. The incubation period ranged from 45 minutes to 5.5 hours, with a mean of 2.5 hours. Chicken burgers, cotton candy, balilah, and shawarma were significantly associated with illness among nine food items consumed as shown in table1. Members from the Saudi Food and Drug Authority took samples from the remaining food, which were chicken burgers, chips, and grape leaves and a laboratory investigation of food samples was negative.
Based on symptoms, incubation period, epidemiological investigation, and laboratory results there might be some differential diagnosis, but we were unable to more definitively identify the source of the outbreak. The current outbreak could be caused by chemicals or toxins found in Chicken Burger, Shawarma, Balilah, and cotton candy. Cross-contamination may explain why so many food items were implicated.
Table 1: Food‑specific attack rates and risk ratios for each food item of the foodborne outbreak in the Primary School for girls, Riyadh, 2023
| Food‑specific attack rates and risk ratios | ||||||||||||
| Food items | Ate specified food | Did not eat specified food | RR | CI 95 | P value | |||||||
| ill | well | total | AR % | ill | well | total | AR% | UL | LL | |||
| Chicken Burger | 62 | 19 | 81 | 76.54 | 83 | 95 | 178 | 46.63 | 1.64 | 2.00 | 1.35 | < 0.0001 |
| Shawarma | 34 | 15 | 49 | 69.39 | 111 | 99 | 210 | 52.86 | 1.31 | 1.64 | 1.05 | 0.018 |
| Chips | 98 | 70 | 168 | 58.33 | 47 | 44 | 91 | 51.65 | 1.13 | 1.43 | 0.89 | 0.31 |
| Corn | 38 | 21 | 59 | 64.41 | 107 | 93 | 200 | 53.50 | 1.20 | 1.51 | 0.96 | 0.11 |
| Doughnut | 43 | 37 | 80 | 53.75 | 102 | 77 | 179 | 56.98 | 0.94 | 1.19 | 0.74 | 0.633 |
| Red juice | 116 | 78 | 194 | 77.85 | 29 | 36 | 65 | 44.62 | 1.34 | 1.79 | 0.99 | 0.05 |
| Grape leaves | 29 | 15 | 44 | 43.18 | 116 | 99 | 215 | 53.95 | 1.22 | 1.56 | 0.96 | 0.11 |
| Balilah | 11 | 3 | 14 | 78.57 | 134 | 111 | 245 | 54.69 | 1.44 | 1.93 | 1.06 | 0.01 |
| cotton candy | 18 | 2 | 20 | 90 | 127 | 112 | 239 | 53.14 | 1.69 | 2.04 | 1.40 | < 0.0001 |
References:
1. Foodborne Diseases and Outbreaks [Internet]. www.cdph.ca.gov. Available from: https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/FoodborneDiseasesandOut…
2. World Health Organization (WHO). Food safety [Internet]. Who.int. World Health Organization: WHO; 2022. Available from: https://www.who.int/news-room/fact-sheets/detail/food-safety
3. Uri.edu.Available from: https://web.uri.edu/wp-content/uploads/sites/25/Causes-and-Prevention-o…
4. Gov.sa. Available from: https://www.moh.gov.sa/en/Ministry/Statistics/book/Documents/Statistica…